Complete issue 30:3 as one pdf - TUG

TEX Education EUROTEX 2009 E21
setlinejoin, setlinecap, or the use of closepaths for
contours, willhelp youout.
Flowchart
Anexampleoftheuseof gkppicmacrosisthefollowing
diagramforthe loop.
The code I borrowed from BLUe’s pic.dat, adapted for
theoccasionwithinserting\bluecand\bluel.Notnice,
so anotherreason fordoing it allinMetaPost.
\def\blueflowchartlooppic%
{\bgroup\unitlength=3ex%3.8ex
\xoffset{-.5}\yoffset{-.3}%
\xdim{5}\ydim{7.5}%
\beginpicture
%\ifmarkorigin\put(0,0)\markorigin\fi
\put(0,0){\line(1,0){2}}%
\put(0,0){\line(0,1){6}}%
\put(0,6){\bluec\vector(1,0){2}}%
\put(2,6.5){\bluec\vector(0,-1){1.5}}%
\put(1,4){\framebox(2,1){\bluec pre}}%
\put(2,4){\bluec\vector(0,-1){.5}}%
%\put(2,3){\rhombus(2,1)1{tst}}%
\put(1,3){\bluec\line(2,1){1}} %lu
\put(1,3){\bluec\line(2,-1){1}} %ll
\put(3,3){\bluec\line(-2,1){1}} %ru
\put(3,3){\bluec\line(-2,-1){1}} %rl
\put(2,3){\makebox(0,0){\bluec tst}}%
%
\put(2,2.5){\line(0,-1){0.5}}%
\put(1,1){\framebox(2,1){\bluec post}}%
\put(2,1){\line(0,-1){1}}%
%
\put(3,3){\line(1,0){1}}%
\put(4,3){\vector(0,-1){3}}%
\put(4,2.5){\kern2pt{\bluec else}}%
\endpicture\egroup%
}% end blueflowchartlooppic
Before the invoke I dened \bluel as well as \bluec
and used \bluec in the denition and \bluel before the
invoke. Notso nice, but imposed by PDF.
Disadvantages of the gkppic macros and L ATEX
picture environment is that coloring is tricky when
using \pdf(Any)TeX: elements of a font are colored by
supplying k to \pdfliteral and lines or lls are colored
by supplying K to \pdfliteral. Moreover, one has to
put the pictures drawn by the wind macros in a box of
appropriate size, sort of Bounding Box, to ensure space.
Anuisance.
\def\bluec{\pdfliteral{1 0 0 0 k}}
%versus
\def\bluel{\pdfliteral{1 0 0 0 K}}
When we use the multi-step processing line via PS we
don’t have that disadvantage. Below atest example.
pretext
\special{ps: 0 0 1 setrgbcolor}%blue
abc
\hrule
def
\special{ps: 0 0 0 setrgbcolor}%black
posttext
\bye
Processthe.dviviadvipsandviewthe.ps,toverifythe
result. In TEXnicCenter I have added the Output Prole
eTEX→PS→PDF. Convenient.
Note the explicit switching back to black, because the
TEX scope rule is not obeyed, of course. Another way to
preventthattherestwillappearinblue,istoinsertgsave
inthe rst and grestoreinthe second \special.
My MP code for the owchart which made use of
Hobby’s boxes.mp.
input boxes.mp;
prologues:=3;
%outputtemplate:="%j-%3c.eps";
beginfig(0)
boxit.boxa (btex \hbox to 60pt%
{\strut\hss pre\hss}etex);
boxit.boxb (btex \hbox to 60pt%
{\strut\hss tst\hss}etex);
boxit.boxc (btex \hbox to 60pt%
{\strut\hss post\hss}etex);
boxa.c=(100,180);
boxb.c=(100,140);
boxc.c=(100,100);
boxa.dx=boxb.dx=boxc.dx=5;
boxa.dy=boxb.dy=boxc.dy=5;
drawoptions(withcolor blue);
drawboxed (boxa, boxc);
%draw contents of b and the diamond shape
draw pic.boxb;
draw boxb.w--boxb.n--boxb.e--boxb.s--cycle;
%The arrows
drawarrow boxa.s--boxb.n;
drawarrow boxb.s--boxc.n;
z1-boxb.e=z2-boxc.e=(20,0);